Loading device for processing machines

ABSTRACT

A mechanism for feeding workpieces to a machine includes a conveyor system for moving workpiece receptacle to a machine at a constant speed and reciprocating loading means for transferring workpieces to the receptacles from a fixed station, the loading means being synchronized with the movement of the receptacles when moving in the direction to feed a workpiece.

O United States Patent [151 3,659,693 Muller 1 May 2, I972 [54] LOADINGDEVICE FOR PROCESSING Relerences Cited MACHINES UNITED STATES PATENTS[72] Inventor: Kl l'l Muller, Theodorenstr 6-8, 6200 2388'! 5H9 Allen2'4 BB wlesbaden, Germany 3,198,308 8/1965 Driesch..... ....l9B/24 [22]Filed: Nov. 3,1969 3,362,519 1/1968 Skarin ..l98/24 PP'- NOJ 873,364Primary Examiner-Richard E. Aegener Attorney-Christen & Sabol ll ti P iit But [30] Foreign App cm on ror y a ABSTRACT ,l3,|969 G .Pl9i2659.1 IMar ermany A mechanism for feeding workpieces to a machine includes a 52us. Cl ..19s/20 w sys'em for moving workpiece receptacle to a [5 1 1 1mCl ""3652 47/00 machine at a constant speed and reciprocating loadingmeans [58] l gearch "198/20. 53/251 252' 59; for transferring workpiecesto the receptacles from a fixed sta- 214/] BB. l BC tion, the loadingmeans being synchronized with the movement of the receptacles whenmoving in the direction to feed a workpiece.

8 Claims, 6 Drawing Flgures PATENTEIJW 2 ma 3. 659.693

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LOADING DEVICE FOR PROCESSING MACHINES The invention deals with aloading device with a loading arm receiving workpieces and transferringthem from a locally fixed receptacle for the workpieces to a processingmachine operating continuously and with a continuous feed of theworkpiece receiving station, which loading arm, during the transfer ofthe workpiece, moves in synchronism with the receptacles.

In the case of automation of processing procedures, the problem willoccur of loading and unloading processing machines operatingcontinuously and with a continuous feed of receptacles for theworkpiece. in these cases, for example, with regard to broachingmachines with long breaching tools, it will not be possible to stop thefeed during the loading process because, as a result of that, one cannotmaintain the precision of production of the workpiece being processed.Rather, the speed of feed must be maintained unchanged and each newworkpiece must be inserted in the receiving space of the workpiece or betaken off from it. For that purpose, the loading arm, carrying out thistransfer, must be in complete synchronism, during the transfer, withsaid receiving station of the workpiece and, at the same time, it candeviate very little from the transfer position. At the same time, asecondary condition often exists, namely that the movements must takeplace very rapidly since the speed of operation should be as high aspossible. These problems of guiding the movement must be solvedsimultaneously if such devices are to operate faultlessly.

It is obvious to solve the problem by accomplishing position andsynchronism of the loading arm and of the receptacle of the workpiecefor the duration of the transfer of the workpiece by means of acontrolled closure of the mold. Arrange ments of this kind have alsobeen known, but such arrangements in actual operation have seriousdefects. lf irregularities occur during the transfer of the workpiecebetween the loading arm and the receiving station for the workpiece,then the intended transfer time can easily be executed and the loadingarm can be driven against the stops limiting the path of movement of theloading arm. Thus the arrangement with its relatively high precisionwill be destroyed and, in most cases, considerable damage occurs, evento the processing machine.

Thus the task exists of establishing the synchronism between the loadingarm and the receptacle for the workpiece in such a manner thatmechanical damage or the destruction of the device be avoided in case ofirregularities in the transfer of the workpiece.

According to the invention, the loading device will be designed in sucha manner that the loading arm is provided with means guiding theworkpiece in a controlled manner and that, during the transfer of theworkpiece, it will be moved by a driving arrangement with a higher speedthan the feeding speed and a smaller force than the feeding force of theworkpiece receptacle, and in that the workpiece receptacle has a stopfor the loading arm.

The advantage of the device consists in that the loading arm, afteroperation of the driving device, comes into positive connection with theworkpiece receptacle with the result that synchronism exists. At thesame time the course of movement of the feed of the workpiece receptacleis not disturbed, and the positive connection of the drive or of theworkpiece in the guide means is not accomplished, whenever the transferprocess has not been completely concluded at the time that the stops arereached by the loading arm. As a result of that, the device and theworkpiece receptacle of the processing machine will remain undamagedwhenever the stops of the loading arm have been reached since a positiveconnection between the loading arm and the workpiece receptacle throughthe workpiece itself can no longer occur anymore either.

It will be advantageous for the means guiding the workpiece in apositive connection to consist of gripping tongs that can be adjusted atvarious degrees of freedom by a gripping tong adjuster.

Through this development of the invention, a precise treatment of theworkpiece has been made possible to carry out the transition.

it is afurther object of the device according to the invention for themovement of the loading arm to be released by a sensor operated by theworkpiece receptacle, which sensor will operate the drive of the loadingarm whenever the stop of the workpiece receptacle happens to be in'thedirection of transportation, behind the loading arm.

Through this development of the invention, the length of time requiredfor the transfer, in which synchronism must exist between the loadingarm and the workpiece receptacle, can be shortened.

In a further development of the invention, the stop of the workpiecereceptacle acts upon the loading arm whenever the loading arm movestoward the workpiece receptacle and it can be forced away by the loadingarm whenever the workpiece receptacle moves toward the loading arm.

The advantage of this stop development consists in that theconstructional dimensions can be decreased since the loading am now canbe in the path of movement of the stop of the workpiece receptacle evenin its rest position.

A further advantageous development of the invention consists in that theoperation of the drive of the gripping long and of the gripping tongadjusters is accomplished hydraulically.

As a result of that, the positive connection can be accomplished withsimple means in an optimum manner since the force of pressure of theloading arm against the stop of the workpiece receptacle and of thegripping tong against the workpiece can be adjusted through surpluspressure in the pressure line so that the pressure of the gripping tongas well as the acceleration of the loading arm to synchronize speed canbe adjusted to the highest possible degree and the feed force acting onthe workpiece receptacle can be adjusted to the smallest possibledegree. Furthermore, the required rapid movement of all parts can becontrolled well as a result of that and especially through the favorabledamping characteristics of hydraulic drives at the beginning and at theend of movement.

It is particularly advantageous whenever the drive of the loading arm isaccomplished by the piston of a linearly operating hydraulic cylinder.

Such cylinders, in contrast to rotating hydraulic motors, are simpleconstructional parts which will suffice for the short strokes of theloading arm.

A further particularly advantageous development of the drive will occurthrough the fact that the piston of the hydraulic cylinder isarticulated to the crank pin of a loading arm executing a revolvingmovement.

As a result, that section of the crank movement of the accelerationphase of a loading arm executing the graduated dial movement can beselected in which the crank has the greatest possible mechanicaladvantage. Therefore, in this phase the greatest possible force of thehydraulic cylinder becomes effective, while for the rest of the movementof the graduated dial, the lesser force of the effectivelyforeshortening lever arm suffices.

In a further development of the invention, the drive is released throughremote control.

As a result, the entire course of the movement of the loading andunloading can be regulated at an optimum in a simple manner.

Furthermore, it will be of advantage to combine various characteristicsof the invention if a precise adaptation of a loading device to thepertinent purpose of use is to be achieved. Especially through the useof the adjustable gripping tong, not only is the loading of a processingmachine possible, but also through a simple change of the sequence offunctions of the device according to the invention, the unloading wouldalso be possible.

A preferred embodiment of the invention has been shown schematically inthe drawing by way of example.

FIG. 1 illustrates a diagrammatic layout of a preferred form of loadingdevice using with a processing machine in accordance with thisinvention;

FIGS. 2 through 4 illustrate various cycles in the work transfer operation;

FIG. 5 is a fragmentary view of the gripping tongs as viewed from theright in FIGS. l- 4, and

FIG. 6 is a fragmentary view of a mechanism for driving the loading arm.

In FIG. 1, numeral 1 indicates a loading device having an elongatedstation 2 for receiving workpieces 20 which are ready for processing.The loading devices includes an operating base 100 having areciprocating loading arm 10], on the end of which there are grippingtongs 102 supported by a swivelling arm 103 attached to an uprightsupport. The power for operating the tongs, the swivelling arm, loadingarm and other devices is supplied by hydraulic lines 104, 105 and 106connected with a source 107, under control of switching mechanism 108,all of the operations being performed by mechanisms which are well knownin the art.

The processing machine 3, which may include a broaching machine 305 isprovided with an endless conveyor means 300 which operates at constantspeed and is provided with a series of workpiece receptacles 302, 303and 304 for carrying a workpiece during the course of operation by themachine. Each of the receptacles is provided with a tripping arm,indicated by numerals 3021, 3031 and 3041, respectively pivotallyattached to each receptacle at 3022, 3032 and 3042 so as to be movablein a counterclockwise direction but restrained against movement beyondthe vertical in the other direction by the respective stops 3023, 3033and 3043.

FIG. 2 shows the start of the transfer process which has been initiatedby switching means 108 to cause the arm 101, carrying a workpiecegripped by tongs 102 to move toward the right, the rate of movement ofthe arm being arranged to be faster than the rate of movement of theconveyor so that the arm will overtake the receptacle 304 until itengages against the upper end of tripping arm 3041 which, because ofstop 3043, will cause the arm 101 to slow to the same speed as thereceptacle and move in synchronism with it because the force developedby the mechanism moving the arm is designed to be less than theresistance offered by the tripping arm. At the same time a sensing means(not shown) causes the gripping tongs 102 to correctly position theworkpiece by manipulation ofthe swivelling arm 103 and to release theworkpiece into the receptacle, which release has occurred in FIG. 3. inFIG. 4 the loading arm 101 has started retraction toward the left; sincethere is no positive connection between the loading arm and thereceptacles, the workpieces are merely carried along away from thegripping tongs. Furthermore, in case the loading arm has not beenretracted before a succeeding receptacle 303 arrives, the tripping arm3031 will pivot to allow the arm 101 to pass. Thus, no damage can occur.

FIG. 5 shows a detail of the gripping tongs mechanism wherein numeral 50indicates a hydraulic cylinder for the piston 51 which operates theclamping jaws 54 and 55, pivotally supported on yoke 58 by bearings 56and 57 and connected with the piston by coupling members 52 and 53. Thecylinder 50 is pivotally mounted on an offset frame 65 for tilting indirections shown by double arrow 60, the frame being offset from thevertical extension of the loading arm 101. A pair of hydraulic cylinders61 and 62 include operating pistons connected with opposite ends of achain 63 which engages with sprocket wheel 64 attached to cylinder 50.The hydraulic cylinders can be operated by differential pressure in awell known manner to avoid lost motion.

FIG. 6 shows a detail of a mechanism for the graduated drive of theloading arm 101, which is shown in its rest position, pivotallyconnected to a support at 1010, with the hydraulic drive being acylinder and piston 100, having one end supported at a point on the axisindicated by dotted line 1000, and connected at 1011 with the loadingarm. Since the axis indicated by dotted line 1001 is at right angles to1000 in the rest position, the acceleration of loading arm 101 will beat a maximum when the cylinder initiates the stroke of arm 101.

I claim:

1. Loading mechanism for feeding workpieces from a fixed station to asuccession of moving receptacles comprising conveyor means for moving aseries of spaced workpiece engaging receptacles in a predetermined pathin one direction at constant speed, loading arm means mounted forreciprocatory movement from and to a stationary location in a pathparallel with said path of movement of said workpiece engagingreceptacles, said loading arm means including workpiece gripping meansfor picking up a workpiece at said stationary station and depositingsaid workpiece in a moving one of said workpiece engaging receptacles,said loading arm means also including means for moving the grippingmeans from said stationary location and in the same direction as theworkpiece engaging receptacles at a faster rate of speed than the speedof movement of said receptacles for overtaking a moving recep tacle,said loading mechanism also including tripping means connected with eachreceptacle for synchronizing the rate of speed of movement of saidgripping means with that of the receptacles when a workpiece engagingreceptacle is overtaken to transfer the workpiece to the receptacle.

2. The invention defined in claim 1, wherein the loading arm meansincludes means for supporting the workpiece gripping means for movementabout vertical and horizontal axes.

3. The invention defined in claim 1, wherein said means forsynchronizing the rate of speed of the loading arm means includessensing means responsive to approach of the gripping means to areceptacle.

4. The invention defined in claim 1, wherein said means forsynchronizing the rate of speed of the gripping means includes atripping arm means on a receptacle for engagement with the grippingmeans moving toward the receptacle, said arm means being retractablewhen the gripping means moves in a reverse direction relative to areceptacle.

5. The invention defined in claim 1, wherein said gripping meansincludes hydraulic actuating means for positioning the gripping meanswith respect to the loading arm means.

6. The invention defined in claim 5, wherein said gripping means ispivotally mounted for rotation about at least one axis, and a pair oflinearly movable hydraullically operated members are connected with saidgripping means for said movement.

7. The invention defined in claim 6, wherein said gripping means is alsopivotally mounted for rotation about another axis, and a hydraullicallyoperated member is connected with the gripping means for said rotation.

8. The invention defined in claim 1, wherein said movement of theloading means and said workpiece gripping means are provided with commonremotely controlled actuating means.

t i i i I

1. Loading mechanism for feeding workpieces from a fixed station to asuccession of moving receptacles comprising conveyor means for moving aseries of spaced workpiece engaging receptacles in a predetermined pathin one direction at constant speed, loading arm means mounted forreciprocatory movement from and to a stationary location in a pathparallel with said path of movement of said workpiece engagingreceptacles, said loading arm means including workpiece gripping meansfor picking up a workpiece at said stationary station and depositingsaid workpiece in a moving one of said workpiece engaging receptacles,said loading arm means also including means for moving the grippingmeans from said stationary location and in the same direction as theworkpiece engaging receptacles at a faster rate of speed than the speedof movement of said receptacles for overtaking a moving receptacle, saidloading mechanism also including tripping means connected with eachreceptacle for synchronizing the rate of speed of movement of saidgripping means with that of the receptacles when a workpiece engagingreceptacle is overtaken to transfer the workpiece to the receptacle. 2.The invention defined in claim 1, wherein the loading arm means includesmeans for supporting the workpiece gripping means for movement aboutvertical and horizontal axes.
 3. The invention defined in claim 1,wherein said means for synchronizing the rate of speed of the loadingarm means includes sensing means responsive to approach of the grippingmeans to a receptacle.
 4. The invention defined in claim 1, wherein saidmeans for synchronizing the rate of speed of the gripping means includesa tripping arm means on a receptacle for engagement with the grippingmeans moving toward the receptacle, said arm means being retractablewhen the gripping means moves in a reverse direction relative to areceptacle.
 5. The invention defined in claim 1, wherein said grippingmeans includes hydraulic actuating means for positioning the grippingmeans with respect to the loading arm means.
 6. The invention defined inclaim 5, wherein said gripping means is pivotally mounted for rotationabout at least one axis, and a pair of linearly movable hydraullicallyoperated members are connected with said gripping means for saidmovement.
 7. The invention defined in claim 6, wherein said grippingmeans is also pivotally mounted for rotation about another axis, and ahydraullically operated member is connected with the gripping means forsaid rotation.
 8. The invention defined in claim 1, wherein saidmovement of the loading means and said workpiece gripping means areprovided with common remotely controlled actuating means.